%Name:		Chris?Shoemaker
%Course:	EER-280?-?Digital?Watermarking
%Project:?	Least?Significant?Bit?Substitution
%???????????Watermark?embeding

clear?all;

%?save?start?time
start_time=cputime;

%?read?in?the?cover?object
file_name=‘_lena_std_bw.bmp‘;
[cover_objectmap]=imread（file_name）;

%?read?in?the?message?image
file_name=‘key.bmp‘;
[messagemap1]=imread（file_name）;
message1=message;

%?convert?to?double?for?normalization?then?back?again
message=double（message）;
message=fix（message./2）;
message=uint8（message）;

%?determine?size?of?cover?object
Mc=size（cover_object1）;	%Height
Nc=size（cover_object2）;	%Width

%?determine?size?of?message?object
Mm=size（message1）;	????????%Height
Nm=size（message2）;	????????%Width

%?title?the?message?object?out?to?cover?object?size?to?generate?watermark
for?ii?=?1:Mc
????for?jj?=?1:Nc
????????watermark（iijj）=message（mod（iiMm）+1mod（jjNm）+1）;
????end
end

%?now?we?set?the?lsb?of?cover_object（iijj）?to?the?value?of?watermark（iijj）
watermarked_image=cover_object;
for?ii?=?1:Mc
????for?jj?=?1:Nc
????????watermarked_image（iijj）=bitset（watermarked_image（iijj）1watermark（iijj））;
????end
end

%?write?the?watermarked?image?out?to?a?file
imwrite（watermarked_image‘lsb_watermarked.bmp‘‘bmp‘）;

%?display?processing?time
elapsed_time=cputime-start_time

%?calculate?the?PSNR
psnr=psnr（cover_objectwatermarked_imageMcNc）

%?display?watermarked?image
figure（1）
imshow（watermarked_image[]）
title（‘Watermarked?Image‘）
figure（2）
imshow（cover_object[]）
title（‘original??image‘）
for?ii?=?1:Mc
????for?jj?=?1:Nc
????????watermark1（iijj）=message1（mod（iiMm）+1mod（jjNm）+1）;
????end
end
%watermark1=watermark1*256;
%message1=message1*256;
figure（3）
imshow（watermark1[]）
title（‘the?watermark‘）
figure（4）
imshow（message1[]）
title（‘the?watermark‘）

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????????801??2002-11-12?18:37??watermark?LSB\fig11.gif

?????文件?????147630??2002-11-12?18:37??watermark?LSB\fig13s.gif

?????文件??????14622??2002-11-18?09:33??watermark?LSB\key.bmp

?????文件??????66614??2002-11-20?09:46??watermark?LSB\lena.bmp

?????文件??????71115??2002-11-02?16:05??watermark?LSB\lena3.gif

?????文件???????1873??2002-11-19?20:13??watermark?LSB\lsb_embed.m

?????文件????????958??2002-11-13?14:06??watermark?LSB\lsb_recover.m

?????文件??????11416??2003-06-25?13:15??watermark?LSB\test.jpg

????..A.SH.?????36864??2010-05-10?16:56??watermark?LSB\Thumbs.db

?????文件??????42240??2001-03-25?15:47??watermark?LSB\_key.bmp

?????目錄??????????0??2010-04-24?20:54??watermark?LSB

-----------?---------??----------?-----??----

???????????????394133????????????????????11